Send test email

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds value beyond annotations by clarifying the tool never charges credits and only sends to a test inbox, which mitigates the destructiveHint. It also specifies the required bearer token scope. No contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, front-loaded with purpose, then safety guarantee, then auth and return. Every sentence adds essential information with no fluff.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers purpose, safety, required scope, and return value. Lacks details on 'variables' parameter, but for a test tool the description is reasonably complete given the context.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 33% (only 'to' has description). The tool description does not explain the 'key' parameter (likely template key) or 'variables' parameter (likely template variables), leaving the agent guessing about their purpose.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Send a test of a template to a verified test inbox' with specific verb and resource, and distinguishes from sibling tools by emphasizing it's a test send that never charges credits or hits real recipients.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains when to use ('validate output during development') and what not to do (never charges credits or hits real recipient). It also mentions the required OAuth scope, but does not explicitly name alternatives or when not to use.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.